Manufacture of dehydrated coffee



Patented July 3, 1945 n 2,319,427` MANUFACTURE or oEnYDRA'rEn corral;

Walterv R. Fetzer, Clayton, Mo., assignor to Union Starch & Refining Company, Columbus, Ind.,

a corporation of Indiana Application October 31, 1942, Serial No. 464,092

s claims. (Cl. 9er-71)y This invention relates to a process for manufacturing solid dehydrated lcoffee whereby the desirable flavor and aroma, constituents are By using corn syrup as an extracting medium the amount of evaporation necessary and the vapor pressure of the ymix is also reduced which,

largely retained by the use of an aqueous corn syrup percolatingmedium in a cyclic process. y

Solid coifee concentrates from whichtcoiee can be made by the addition of hot water have been.previously suggested in the art. have; however," been largely unacceptable because they lack the flavor and aroma constituents of coffee freshly made by the customary percolating or brewing processes. This loss of flavor and aroma constituents constitutes the most serious single problem in the 'manufacture of coffee concentrates.

In all of the processes of forming a solid coffee concentrate the volatile constituents which pro- They duce the aroma and flavor of coffee are largely lost by volatilization duringv the manufacturing process.

Although attempts have been made to recapture the volatilized constituents and later join these fractions to the coffee base for subsequent dehydration, a large portion of the volatiles still are lost and the apparatus for collection of this volatile fraction is rather cumbersome and'does not lend itself to a simple continuous process.

It is the object of the present invention toextract and retain the volatile and'non-volatile `portions of the coffee flavor in the manufacture of a solid coffee concentrate.

It is a further object of the present invention to reduce the vapor pressure of the liquid colee mix which, in turn, reduces the losses of the desirable volatile constituents. g t It is a further object of the presentinvention o to retain the desirable flavor and aroma constituents by the use of a lxative ag nt. Y

It is a further object of the pre ent invention to provide a process for-the dehy l tion of coli'ee lin which the amount of evapor 4tion necessary to carry the concentrate to dryness is reduced.

Other objects of this invention will be apparent from the specic description of the process set forth hereinafter. o

These objects are accomplished by. employing ,corn syrup or a mix of corn syrup and water as the extraction medium used in a simple counter current process to extract the necessary collec components from solid ground coffee beans. The corn syrup, containing-as it does the reducing sugars maltose and dextrose, xes to a marked degree the volatile aroma and flavor constituents, in addition to serving as a base for the dehydration of the coffee to solid form.

l the combinedextracts is approximately now 23' about 20 B. o Y The hot corn syrup extraction liquor circulating through` the pulverized coffee, extracts both in turn, substantially reduces the losses of the g volatile constituents. I l

The counter current process of extraction which will be speciiicallydiscussed hereinafter is diagrammatically illustrated in the flow sheet of the attached drawing. Y

' The process is as follows: 100 pounds of pulverized coffee b eans are placed in the percolator I.

350 lbs. of any extraction liquor is delivered from tank 2 `into the percolator I, the extraction liquor being made up of lbs, of 43 B. regular corn syrup referred to in the art as C. S. U.',.20 lbs. water and300 lbs; washings which are obtained from a rewash of the residual ground Y coffee solids from a previous run, as will be set out more speciiically hereinafter. This combination makes more than the L350 lbs. of extraction liquor delivered to percolator I, but the remainder is utilized as will be shown later. The percolator v I is jacketed and theextraction liquor comprising corn syrup`, water and coffee washings is circul-ated through the `percolator I by pump 4 for a period of one hour at a temperature of below the boiling point, as for example F. lI have found that best results are obtained by using a corn syrup water mix having a concentration of between 10 and `30 Baume, and preferably the soluble coiee solids and the volatile avor and aroma constituentsl to a large extent, and after extraction has'been properly effected at this stage the extraction liquor containing the `coiee coml` ponents is drawn into a vacuum pan 5.

Into the wet mass of coffee remaining in the percolator I is now run another 120 lbs. of extraction liquor from tank-'2.' This extraction liquor displaces the heavy residual extract remainingr in the pulverizedr coffee mass and this liquor is drawn'ofl and combinedwith the original extraction liquor in the vacuum pan 5. The Baum of yat 100 F.

Vacuum andheat, are then applied to the vacuum pan 5 land evaporation proceeds until Athe liquor reaches a lBaume of about 43. liquor. corn syrup containing the soluble and volatile coffee components is then drawnoii to a dehydrator 6 vwhere itis boiled under a high vacuum of oneV an'd one-half inches of mercury'or less whereupon it expands into va cellular mass The heavy .-to bring the Baume ofthis combined liquor :to

' which, inturn, reduces the losses of lthe "desirwhich has mainly intercommunicatingcelis which can be thoroughly dried and pulverized in a process described in the copending applications of Wilbert A. Heyman, Serial No. 351,265 and 381,- 061.

The moisture content is reduced by this expansion and dehydration process to a point below 5% and preferably on the order of 1%. The ratio of corn syrup solids to coiee extract solids is approximately seven to one. I v

The pulverized residual coffee massin percolator I is then treated with 320 lbs. of fresh water g by percolation, which extracts additional; soluble cal and continuous. a coffee constituents. This extract is then drawn It will be understood that the examples and deof! into tank 2 and to this extract is added 150- 15 scription of the process above set forth relate to lbs. of 43 B. corn syrup and about 20 lbs. of water a particular method utilizing the present invention. The various modifications within the scope of this inventionk will be obvious to those skilled in the art from the principles above set forth.-

I claim:

l. The process of manufacturing solid dehydrated coffee which comprises extracting the coffee constituents' of ground coffee with a corn syrupsolution and dehydrating the resulting relatively small proportion of water greatly reduces the amount of evaporationA necessary,

stituents by evaporation, and (4) the corn syrup for the expansion and dehydration process which The cyclic orcountercurrent process described obtains the maximum strength of the coffee com- 10. ponents in the extraction liquor while reducing the amount of 'evaporation necessary for concentration and'makes the process eilicient, economiapproximately 20 Baume at 100 1i.v

This extraction liquor is -then used on 100 lbs. of pulverized coffee which has been placed in per- 20 colator 1, the extraction `liquor being' passed through the coffee in this percolator for a period of one hour at 195 F. by the pump 8.

The corn syrup extraction liquor containing'the soluble and volatile coii'e constituents is then 25 @Offee Corn syrup mixdrawn of! into the vacuumi'pan 5l and .to .that is '2. The process of manufacturing solid dehyadded a second extraction liquor as was previ:A ously described in' connection with the description f and Water, extracting by -liirculuiliun the Soluble cf the operation in percolator I. The combined C0566 Constituents 0f ground coffee and dehydratextract is .then concentrated in the vacuum pan 5 3o ing the resulting coffee 'corn Syrup mix under heat and then delivered to the dehydrator E where it is and Vacuumthen dehydrated and expended to solid form.- r 3. The process of manufacturing-solid dehyhave found that the corn syrup mix most; effective drated coiee which comprises extracting the-solfor accomplishing my obje/cts is 20 Baume. uble coffee constituentsof ground coffee with It will be obvious that'eny number of perco- 35 aqueous corn .Syrup and dehvdrating the resultlators may be used.v By the process here sot forth ing coee corn syrup mix, rewashing the remainthe soluble and volatile constituents ofthe coffee ing ground coiee with aqueous 00m Syrup und are extracted in such a manner as to obtain a. using the aqueous corn syrup wash thus Obtained lsubstantial' proportion of these constituents of as a medium for extracting the soluble coffee conthe pulverized coffee 'and`in such a way that 4c stituents of a second bath of ground coffee. because of the low vapor pressure andlthe low 4. In the process of making a dehydrated coiee heat employed a relatively large proportionof with high volatile flavor content, the step lof -ex' Volatile` avor and aroma constituents are rotracting soluble coffee constituents, from ground tained. The retention of these constituents is C0569 With aqueous (50m` Syrup Whih hasibeen facilitated by the reducing sugars contained in 45 passed over ground coffee from which the soluble the 50m Syrup which is animportant component; coffee constituents have been previously substanof v,the extraction liquor. These `reducing sugars tia'lly. extractedtlx the volatile avor and aroma constituents. By employing thecoffee washings of the previ-v ous run in forming the new extraction liquor for 50 coifee constituents from ground coffee with aqueeach subsequent -run optimum results are obous corn syrup having a concentration of vabout Lained. The greatest proportion of coffee com 20 B. anddehydrating the resulting coffee corn smuents is obtained and retained. i /SYI'UD miX- It willbe noted that the process here set forth 6. The process of manufacturing solid dehyiS primarily based upon (1) the use of-corn syrup` 55 drated coffee which comprises extracting soluble v coiee constituents from ground coifee with aqueous corn syrup having a concentration of about 20 B. and passing a secondn batch'of aqueous as an important component of the extraction medium whereby. the vapor pressure `is reduced,

able volatileconstituents (2) the reducing sugars the iiavor and aroma constituents ofthe coiee aqueous com Syrup containngsoluble coffee con' during the extraction and hence are in a position 'to' best nx and retain these constituents cornsyrup mix. (3) the liquid corn syrupcontaining .as it does a WAL'I'ER n. Farm.

which, in turn, prevents loss of the volatile con- 5 used in the extraction medium serves as the base i' is used to convert the coiee extract to solid form.

drated coffee which comprises mixing corn syrup 5. The process of manufacturing solid dehy- -drated coffee which comprises extracting soluble com syrup through the spent ground coffee, comcontained in the Vcom syrup are 1n Contact with oo bining the nrst batch and the second batch of y stituents and dehydrating the resulting coffee 

